Impact bits with a torsion zone, to allow the screwdriver bit to flex for reduced breakage and to withstand the changes of load associated with high torque use. Long Service Life Torsion zone for increased durability Specially designed for impact drivers Precision profile for better fit Magnetic tip to aid holding and starting DIN 8764 standard Taiwan S2 grade steel construction HRC60-61 hardened for optimum strength Black phosphate coating for corrosion protection and increased life Storage case Details: Drive: 1/4" Hex Length: 25mm Profile: PZ2 Quantity: 20 pieces Box contains10 packs of 20